2.4.18-pre3-ac2 performance regression(?) vs. 2.4.17

[florin@iucha.net (Florin Iucha)]

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Rik, Alan,

I have downloaded 2.4.18-pre3-ac2 out of curiosity for the VM and IDE
performance.

As a "benchmark" I ran hdparm -Tt /dev/hda. The results were surprising:

2.4.17

/dev/hda:
 Timing buffer-cache reads:   128 MB in  0.86 seconds =148.84 MB/sec
 Timing buffered disk reads:  64 MB in  3.95 seconds = 16.20 MB/sec

 Timing buffer-cache reads:   128 MB in  0.90 seconds =142.22 MB/sec
 Timing buffered disk reads:  64 MB in  4.05 seconds = 15.80 MB/sec

 Timing buffer-cache reads:   128 MB in  0.88 seconds =145.45 MB/sec
 Timing buffered disk reads:  64 MB in  4.00 seconds = 16.00 MB/sec

2.4.18-pre3-ac2

/dev/hda:
 Timing buffer-cache reads:   128 MB in  0.99 seconds =129.29 MB/sec
 Timing buffered disk reads:  64 MB in  3.90 seconds = 16.41 MB/sec

 Timing buffer-cache reads:   128 MB in  0.93 seconds =137.63 MB/sec
 Timing buffered disk reads:  64 MB in  4.03 seconds = 15.88 MB/sec

 Timing buffer-cache reads:   128 MB in  0.92 seconds =139.13 MB/sec
 Timing buffered disk reads:  64 MB in  3.90 seconds = 16.41 MB/sec

So while I see a slight (un)expected improvement in IDE performance, I
also see a degradation in memory? performance.

The box is a PIII/700MHz laptop with 256 Mb RAM. hdparm is version 4.5

Cheers,
florin

-- 

"If it's not broken, let's fix it till it is."

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